There will be a bus taking the participants from the recommended hotel area to ICMAT and back. In case you want to go there on your own, the following instructions may be useful:
In order to reach to the Institute you can take the train to reach Cantoblanco Universidad station. You can look for the train schedules here. The trains are usually named by its final destination; you can have a look at the whole web here. We advise you to buy a 10-trip-ticket which costs 13,45 euro (a single one is 1,80 euro).
Then, you can walk from Cantoblanco Universidad station to the ICMAT following the map below. It is about 15-20 minutes walking.
On this link you will find other options in order to arrive the ICMAT building.